The specific objectives of my research are: 1. Continue to define conditions necessary for differentiation of neuronal and glial cells from embryonic and postnatal rat CNS germinal cells in dispersed cell and clonal culture. In these experiments differentiation of neurons and glia will be described by the following parameters: (a) morphology; (b) development of high affinity uptake mechanisms for neurotransmitters or their precursors; and (c) changes in affinity for various lectins. In addition, changes in patterns of axoplasmic flow of particulate material will be examined in differentiating neurons. 2. Attempt to transform rat neuronal of glial cells "in vitro" at different times during the differentiation process to determine: (a) if there is any correlation between the initial phenotype of the transformed cells and the inital state of differentiation at transformation, and (b) if any changes in the transformed cell phenotype are correlated with changes in the untreated controls. Characteristics defined in studies relating to (1) will be re- examined, where appropriate, in the transformed cells to define the transformed phenotype. The methods to be used include dispersed cell or clonal culture, cell transformation by chemical carcinogens, histochemical analysis through the use of fluorescence microscopy and light and electron microscope radioautography.